An integrated circuit (“IC”) die is a small electronic device formed on a semiconductor wafer, such as a silicon wafer, which has formed therein electronic circuitry for performing specified operations and functions. Often, a leadframe is coupled to the IC die for providing external electrical connections to input/output (“contact”) pads on the IC die.
FIG. 1 illustrates a simplified exemplary configuration 100 of an IC die 101, which in this example is packaged as a ball grid array (“BGA”), provided to illustrate certain heat dissipation problems with such IC die. The IC die 101 is mounted onto a laminate material 102, such as a substrate, board, or carrier, which has conductive balls 104 mounted thereon, which electrically interconnect to circuitry on a substrate 103. The IC die 101 may then be encapsulated within a mold 105.
The high operating temperature of the IC die 101, caused by the combination of ambient conditions and device power dissipation, is an important reliability concern. For instance, instantaneous high temperature rises can possibly cause catastrophic failure, as well as long-term degradation in the chip and package materials, both of which may eventually lead to failure. FIG. 1 also shows typical heat flow paths in such an IC die package 100 for a typical system without an exposed heat spreader or heat sink. As can be seen in FIG. 1, because of the encapsulation of the IC die 101 within the packaging, the vast majority of the heat dissipation must occur through the connections 104 and the substrate 103 on which the IC die 101 has been mounted. The stacking of multiple IC dies on top of one another in such a configuration exacerbates the foregoing problems associated with dissipation of heat.